The decisive advantage of the PDV procedure in conjunction with a static assignment over a dynamic assignment is its lower complexity. In a dynamic assignment, details in the network modeling play a much more important role than in static assignments. In addition, static assignments usually require significantly less computation time than dynamic assignments.
On the other hand, the PDV procedure does not fully represent the dynamics of traffic. There are three main aspects in which a dynamic assignment is superior to a static one:
- Transfer of surpluses to the following analysis time interval if vehicle journeys have not yet reached their destination
- time-of-day specific travel times
- time-of-day specific route selection
The PDV procedure extends a static assignment by the first of the items mentioned. However, travel times and route selection remain constant over the entire time range. This is particularly noticeable for time periods with a high volume capacity ratio: travel time extensions typical for the time of day as well as shifts to the subordinate road network are not depicted in a time-differentiated manner but are distributed evenly over the entire analysis period.
Thus, the PDV procedure is particularly suitable for strategic transport models where time-of-day travel time fluctuations are not the focus of the analysis. In addition, the method can be applied to models with relatively small fluctuations in travel time over the analysis period. These include, for example, national models that focus on cross-country travel. Another example is models with rather short analysis periods with approximately constant travel times.
